An individual gift is US$1 million and a corporate-sponsored gift is US$2 million, so the individual route is cheaper on its face. The processing fee of US$15,000 per person is nonrefundable either way and is not credited against either gift. The real question is corporate and tax as much as immigration.
Two amounts, and a fee that is neither
Put the arithmetic down before the reasoning. On the individual route the applicant makes a gift of US$1 million; where a corporate sponsor makes the payment on the applicant’s behalf the amount is US$2 million. Add US$15,000 per person for processing, which is nonrefundable and separate. Only then does the interesting question arise, which is where the money currently sits and what it costs to move it. Funds inside a corporation cannot simply be redirected to a personal gift without consequences, and those consequences belong to an accountant rather than to an immigration adviser. Get both opinions before choosing.
Hypothetical example: an applicant from Roxton Pond is offered corporate sponsorship by the American company that wants to engage him, on the footing that the payment will be carried as a recruitment cost. Priced out, the corporate gift is twice the individual amount, and the difference is the company’s to justify rather than his; what he needs to establish separately is which route his own resources could support if the offer is later withdrawn. Take both figures from the current official programme materials and date them, because the terms of a new framework are not a fixed background condition.